1. Technical Field of the Invention
This invention most generally relates to apparatus and methods of catheterization and related treatments of the genitourinary and gastrointestinal passages of mammals. More particularly, the invention relates to catheters, dilators, occluders, stents, suprapubic catheters, camera introducers and related medical devices subject to being proximally propelled and directed for advancement and control in mammalian genitourinary and gastrointestinal passages.
2. Description of the Prior Art
In most mammals, mucous membranes line all those passages by which the internal parts communicate with the exterior, and are continuous with the skin at the various orifices of the surface of the body. They are soft and velvety, and very vascular, and their surface is coated over by their secretion, mucus, which is of a tenacious consistence, and serves to protect them from the foreign substances introduced into the body with which they are brought in contact.
They are described as lining the two tractsxe2x80x94the genitourinary and the gastrointestinal; and all, or almost all, mucous membranes may be classed as belonging to and continuous with the one or the other of these tracts. Catheterization of any of these similar bodily passages may at times be useful or necessary.
Urinary outlet problems most likely have been around for as long as humans. History has the ancient Chinese using onion stalks to relieve people of acute urinary retention.
Literature refers to such problems as far back as 206 B.C., more than 2000 years ago. Romans used catheters, first invented by Erasistratus, a Greek doctor in the third century B.C. Roman catheters were fine tubes made of bronze. The Roman gynecologist Soranus describes how catheters could be used to push stones out of the way and back into the cavity of the bladder, and thus restore urine flow. Excavations in Pompeii unearthed several bronze catheters. These instruments were well constructed but relatively simple and showed that designs changed little from the period 79 AD until 1700 A.D.
However, during the 17th and 18th centuries catheter construction became more complex with an intensified search for an appropriate substance that would be at once flexible, non-irritating and functional. England, France, and the U.S.A. had individuals and companies deeply involved with urinary catheters during this period. Many variations were produced but they all caused much stress on the patient when these rigid devices were pushed into the urethra. The first practical breakthrough was by the French using gum elastic cathetersxe2x80x94a catheter that would bend better in the urethral channel and not scour the mucosa so much in the process.
Charles Goodyear improved upon what the French produced when he successfully vulcanized crude rubber. The problem of manufacturing an instrument which was both sufficiently rigid to enable it to be pushed through the urethra into the bladder and yet flexible enough to negotiate the path, had at last reached the point of practicality, not withstanding its shortcomings. At that time, and still to this day, a functional urethral catheter is defined as one that is flexible enough to negotiate the bends and stable enough to push through the length of the urethral passage.
The French urologist J. J. Cazenave, with the hopes that his country would regain leadership in the catheter field, dedicated 25-30 years of his life improving the flexible durable catheter. This was in the late 1800""s and his catheter, made of decalcified ivory, was a dated device but shows the consistency of the state of the art wherein catheters are pushed into and negotiated along the urethral passage toward the bladder.
During the past 300 years or so, intensified development efforts were stimulated by professional pride, national pride and financial rewards. These efforts yielded many improvements, such as changes to size, curve shape, materials of construction, smoothness, lubricants, coatings, combinations of materials, physical properties, chemical properties and more, yet all subscribed to the basic principle of external push-to-advance.
The catheters of the prior art are large and stiff, difficult and uncomfortable to administer, and uncomfortable to wear for extended periods. There is a degree of skill, tolerance and patience required that takes much time, training and practice to learn. The difficulty, discomfort, risk of injury and infection, inhibition and inconvenience of the methods and tools of the known art results in the deprivation for many patients of the freedom to work, play and travel as do unaffected people.
The anatomy of the adult male urinary tract, as illustrated in FIG. 1, has a bladder 004 where urine is collected prior to exiting the body via the urethra 006. The bladder 004 converges into the urethra 006 at a muscular exit called the bladder neck 005. Approximately the first one inch of the urethra lies within the prostate 007, which is a chestnut-sized gland. The next approximately half inch passes through the external sphincter 008, which is the muscular flow valve that controls the release of urine. The remaining six inches of the urethra lie in a spongy zone, exiting the body at the meatus 009.
The normal process of emptying the bladder can be interrupted by two causes. One is bladder outlet obstruction and the other is failure of the nerves linking the bladder to the brain. The most frequent cause of bladder outlet obstruction in males is enlargement of the prostate gland by hypertrophy or hyperplasia. In older males, it is not uncommon for a progressive enlargement of the prostate to constrict the prostate urethra. This condition, known as benign prostatic hyperplasia (BPH), can cause a variety of obstructive symptoms, including urinary hesitancy, straining to void, decreased size and force of the urinary stream and in extreme cases, complete urinary retention possibly leading to renal failure.
The most common surgical intervention for BPH, transurethral resection of the prostate, or TURP, has a lengthy recovery period of up to one year, and presents a high operative risk for complications such as sexual dysfunction. Up to 10% of those subjected to such surgery are left with mild to moderate stress incontinence. Approximately 400,000 patients in the United States and approximately 500,000 patients internationally were diagnosed in 1994 with BPH or cancer-induced bladder outlet obstructions that were sufficiently severe to warrant TURP or alternative surgery, according to industry sources.
Because of the high costs, medical risks and quality of life compromises associated with TURP, new technologies have begun to challenge TURP""s position as the standard treatment for severe BPH. Recently, the U.S. Food and Drug Administration approved two drugs, tera zosin hydrochloride and rinasteride, to treat BPH. These drugs generally do not improve symptoms for six to nine months after treatment begins, and are not without side effects.
Urethral strictures are another cause of outlet obstruction, often due to fibrous tissue growth resulting from reaction to catheters or cystoscopes or from injury, birth defects or disease, and are commonly treated by urethral dilation, catheterization or surgery. Men with urethral strictures also experience a limited ability to urinate, which may cause extreme discomfort and, if left untreated may cause complications that necessitate catheterization. Approximately 50,000 patients in the United States were diagnosed with recurrent urethral strictures in 1994, according to industry sources. The inventor estimates that approximately 75,000 additional patients were diagnosed internationally.
Women suffer from urinary incontinence far more often than men and at an younger age primarily because of the stress associated with pregnancy and childbirth, the shorter length of the female urethra, and the absence of a prostate. The U.S. Department of Health and Human Services (HHS) estimates that the involuntary loss of urine affects approximately 10 million Americans of which 8.5 million are women. Seven million of these women are non-institutionalized, or community-dwelling.
For women between the ages of 15 and 64, the prevalence of urinary incontinence is estimated to range from 10 to 25 percent of the population. For non-institutionalized persons over the age of 60, the prevalence of urinary incontinence ranges from 15 to 30 percent, with the prevalence in women twice that of men.
The involuntary loss of urine can be caused by a variety of anatomical and physiological factors. The type and cause of urinary incontinence is important to how the condition is treated and managed. The two broad categories of urinary incontinence are urge and stress incontinence. Some people suffer from what is termed mixed incontinence or a combination of stress and urge incontinence.
Urge incontinence is the involuntary loss of urine associated with an abrupt and strong desire to void. In most cases, urge incontinence is caused by involuntary detrusor (the smooth muscle in the wall of the bladder) contractions or over-activity. For many people, urge incontinence can be satisfactorily managed with pharmaceuticals.
The more frequently occurring stress incontinence is the involuntary loss of urine caused by movement or activity that increases abdominal pressure. The most common cause of stress incontinence is hypermobility or significant displacement of the urethra and bladder neck during exertion. A less frequent cause of stress incontinence is intrinsic urethral sphincter deficiency (ISD), a condition in which the sphincter is unable to generate enough resistance to retain urine in the bladder.
Females, and males with no benign prostatic hyperplasia condition, might also have the inability to empty their bladder because of the nerves linking the bladder to the brain. This condition is known as neuropathic bladder, may occur in a wide variety of conditions which include spina bifida, multiple sclerosis, spinal injury, slipped disc and diabetes. When these and other problems prevent the bladder from effectively controlling urine there are a number of treatment options. They are catheters, dilators, occluders, and stents.
Indwelling Foley-type Catheters
During continuous catheterization an indwelling catheter is retained in the bladder by a water filled balloon. It drains urine continuously from the bladder via a connecting tube into a bag which is attached to the leg or bed. The bag has a tap so that the urine can be emptied at intervals. The catheter is usually inserted by a doctor or nurse and changed about every four to six weeks. But difficulty in placement has always been inherent in this design. This is due to the traditional xe2x80x9cpush to advancexe2x80x9d technology which necessitates a relatively stiff, thick-walled catheter to traverse the delicate mucosal lined urethra.
Often the French (unit of measurement) size of the catheter is dictated by the need for stiffness to insert rather than the lumen size to pass urine. A 14 French or smaller Foley is rarely used because catheters of this size lack the column strength needed to push the full length of the urethra into the bladder. The larger French Foley catheters are painful to place, uncomfortable when indwelling, and require a highly skilled care provider to insert.
Intermittent Catheters
During intermittent catheterization a simple catheter made of plastic, rubber, or metal is inserted by the patient or a helper for just long enough to empty the bladder completely, which is typically about one minute. These tubes are usually smaller in diameter and stiffer than an indwelling catheter of the same size. This stiffness can make catheterization difficult in men because the urethra is long and has an acute bend within the prostate. When the external sphincter is reached the sphincter muscle will contract making passage difficult.
Most patients learn to catheterize themselves and thereby gain a large degree of independence. This process is repeated about every 3-4 hours during the day and occasionally as needed at night.
Intermittent catheterization is mainly used by people who are incontinent due to neuropathic bladder. Intermittent catheterization may also be utilized by people who cannot empty the bladder because the bladder muscle is weak and does not contract properly. In some patients, an alternate apparatus and method used to maintain long term drainage of the bladder is the use of a suprapubic tube.
Suprapubic Catheters
Suprapubic catheterization of the bladder is performed via transabdominal puncture which enters the body above the pubic arch and is directed into the bladder using ultrasound or fluoroscopy to guide the trocar introducer and suprapubic catheter. The needle introducer is then removed when proper catheter placement within the bladder is confirmed, leaving the drainage catheter in place.
Long term drainage may require the fixation of the catheter at the skin using standard adhesive based interface components to address mechanical fixation, inflection control, and skin compatibility. The distal end of the catheter is commonly contained within the bladder by inflated balloon, winged-shaped tip configurations which expand within the bladder, or pre-shaped curved catheter tips which curl to their original J-shape when stiffening wire is removed from the catheter lumen.
A problem with this form of distal end emplacement through the bladder wall is that it is only unidirectional; that is, it only resists the inadvertent pulling out of the tip of the catheter from the wall of the bladder, while allowing the catheter to freely pass further into the bladder, and back out up to the point of the containment structure. This continuing catheter motion in and out of the bladder puncture site may irritate tissue and cause infection or other difficulty at the bladder-catheter interface. Urine is especially irritating to most parts of the human body that are outside the urinary tract.
Dilators
Dilation is accomplished by pushing successively larger urethral dilation tubes through the urethra to increase the size of the lumen, a procedure which is painful and traumatic to the patient. Surgical treatment of strictures involves surgical risks as well as complications, including infection, bleeding and restenosis, which requires further treatment.
With the exception of balloon catheters, the current art of dilators has also changed little over the passage of time. A shaft with an increasing taper, bulbous structure, or enlarged end is pushed from without the passage to advance the tool through the restricted passage, thus forcing by longitudinally-applied pressure the lateral expansion of the passage walls. This push-to-advance method necessitates a stiff shaft which has all the same liabilities as traditional catheters. Catheters inherently provide a degree of this dilatorial function to the extent that the passage is opened sufficiently to accommodate the catheter.
Occluders
Occluders are used in some cases to control incontinence. Occluders of the prior art are constructed and applied with the same push-to-advance concept as catheters and dilators described above, with the same liabilities. The basic occluder is a bulb or plug on a shaft which is inserted within a passageway to stop or prevent the normal flow of materials through the passageway, or driven all the way into the bladder, for example, and allowed to seat as a plug at the neck of the urethra to prevent the flow of urine from the bladder.
Stents
A stent is a tubular metallic mesh device that is implanted to open and support a stricture to allow for urine flow. The stent body is between 3.5 cm and 6.5 cm in length depending on the anatomy, and is expandable by design to anchor in place. The stent being a mesh has openings that allow the tissue to grow through the wall making removal difficult and causing encrustation that reduces urine flow.
Intraurethral Valved Catheters
An intraurethral valved catheter is a device that is implanted to control the flow of urine with an integral valve that is remotely actuated. Since the entire catheter length is within the urethra, the chance for external infection is reduced. The anchoring mechanism of current designs is accomplished with balloons, or xe2x80x9cpetal likexe2x80x9d projections from the catheter. Both designs are complicated to install and difficult to remove, and if the valve fails, leaves the patient in a painful and dangerous situation.
Patents in the Prior Art
There has been patent activity in the prior art indicating dissatisfaction with the push-to-advance methodology. Catheters have been adorned with a wide assortment of spiral and threaded features described as intended to ease the trauma and pain of what clearly remained a push-in device. Alvord""s U.S. Pat. No. 207,932 (US), Peyret""s 564,832 (French), Hayes"" U.S. Pat. No. 1,644,919 (US), and Jacoby""s U.S. Pat. No. 1,888,349 (US) are representative of these. In all cases, these disclosures fail to recognize that the basic push technique is fundamentally flawed and should be abandoned, and fail to resolve the critical features of structure necessary for rotational advancement as a substitute for the push method.
Other art reveals the use of spiral features for different purposes. For example, Spinosa""s U.S. Pat. No. 3,815,608 (US), discloses a catheter with a thread designed to hold the urethral wall away from the shaft to allow urine to flow around the outside of the catheter. These disclosures likewise reveal a reliance on push-in methods or an assumption that such structures can be pulled out without regard to the spiral features, again failing to recognize rotation as a viable substitute for push, and failing to resolve the critical features of structure necessary for effective rotational advancement.
As a further indication of the failure of prior art similar to the above inventions to provide effective improvements to push-in methods, there is no apparent indication among the products commercially available, or in the medical practices known to the applicant, that any of these spirally ornamented devices were ever found to be viable.
Gastrointestinal Endoscores
The current device used for inspection and treatment of the GI (gastrointestinal) tract is a flexible Endoscope. This device takes a high level of skill to use, is difficult to maneuver and can be very painful for the patient, due to the basic push-to-advance design that has not changed since the device was invented in the early 1960s. The distal tip of the endoscope has the following parts:
1. a channel opening for suction and passage of accessories,
2. the light guide lens to distribute light from the fiberoptic bundle to illuminate the visual field,
3. the objective lens to focus an image of the mucosa onto the face of the image bundle and transmit it back to the eye piece,
4. an air/water jet, which supplies air to inflate the organ being observed, and water to clean off the image lens.
The Bending Section is the distal end of the tube, ranging from approx. 8-15 cm long, which can articulate to steer the scope as it is pushed inward and is controlled by a cable mechanism that is connected to control knobs on the proximal handle.
The Insertion Tube, which makes up the rest of the 60-150 cm length, is not capable of controlled deflection. It has a tailored bending flexibility and torque transmission which is of major importance in endoscope design. Most instruments have two-stage bending stiffness, i.e., the distal portion of the insertion tube is more flexible than the proximal portion. The Flexibility of each portion of the insertion tube requires extensive clinical testing to ensure that the endoscope handles easily and produces a minimum of patient discomfort.
The colon is a tubular organ which runs from the cecum in the right lower quadrant to the rectum. It is widest in the cecum and ascending colon and gradually narrows as one approaches the rectum. The colon is divided into the following sections:
a. the cecum; the ascending colon, which runs cephalad (towards the head) from the cecum to the hepatic flexure;
b. the transverse colon, which runs from the hepatic flexure in the upper quadrant of the splenic flexure in the left upper quadrant;
c. the descending colon, which runs caudad(toward the feet) from the splenic flexure to the left lower quadrant;
d. the sigmoid colon, which runs from the left lower quadrant to the rectosigmoid junction; and
e. the rectum, which extends down to the anal canal.
The inner layer of circular muscle is present throughout the colon. The outer longitudinal muscle in the wall of the colon is fused into three bands, the teniae coli. These bands start at the base of the appendix and run in the wall of the colon down to the rectum where they diffuse into the muscular coat. The three teniae cause the colon to have a triangular appearance endoscopically; this is especially prominent in the ascending and transverse colon. The haustra are outpouchings of the colon, separated by folds. In the descending colon the endoscopic appearance is often tubular.
Most experienced colonoscopists use similar endoscopic techniques. Air is introduced to inflate the colon, but as little as possible to prevent overdistension. The pressure on the device is gentle to avoid stretching the colonic wall or mesentery (the connective tissue that holds the colon like a fan) which can cause pain, a vagal episode, or a perforation. The lumen is kept in view at all times; little or none of the examination is performed blindly, because you are pushing a stiff instrument.
A variety of in and out maneuvers are used to xe2x80x9caccordianxe2x80x9d the colon on the colonoscope, keeping the colonoscope free of loops as possible. In the difficult colon, special maneuvers such as the creating of an alpha loop in the sigmoid colon are used to pass the sharply angulated sigmoid/descending colon junction. This maneuver may require fluoroscopic guidance and training in the technique.
The colonoscope is advanced to the cecum under direct vision. The detailed examination of the mucosa is usually performed as the colonoscope is slowly removed from the cecum.
To inspect the whole length of the large intestine requires a highly skilled practitioner, which makes the procedure costly. Even still the procedure can be very painful for the patient, making sedation necessary. This is due to the inherent deficiencies in the xe2x80x9cpush-to-advancexe2x80x9d design.
In summary, there are problems in making present push-in catheters, dilators, and occluders stiff enough for penetration and flexible enough to make the turns without undue risk of trauma to the wall of the passageway when being pushed in; and once installed, comfortable enough to wear for an extended period. The problems with stent encrustation and removal are well known. Self-administration is inhibited by all of the short-comings of the prior art. Further injury, infection and discomfort can result from unskilled or improper technique. The problems with colonoscopy have been previously described.
The long history of push-in catheters/dilators and occluders has gradually crystallized into an industry wide, self-perpetuating, fundamental assumption that catheters are to be mainly pushed through bodily passageways, albeit with some rotational easing. This xe2x80x9cfactxe2x80x9d is so widely perpetuated and pervasive in the commercially available products and medical practices as to have stifled original thinking in this art. This, in spite of it""s well-recorded short comings of pain, trauma, risk of rupture, and failed, aborted or incomplete procedures and need for skilled practitioners and special equipment for monitoring and safeguarding against the inherent problems.
For the purposes of this disclosure, including the appended claims, the terms xe2x80x9cdistalxe2x80x9d, xe2x80x9cdistallyxe2x80x9d, and xe2x80x9cdistal endxe2x80x9d, as they relate to the devices and methods described herein, refer to the end of the device further from or in the direction away from a practitioner who might be applying the device or method to the subject. Stated otherwise, the terms refer to the end of the device closer to or in the direction towards the subject""s interior.
The terms xe2x80x9cproximalxe2x80x9d, xe2x80x9cproximallyxe2x80x9d, and xe2x80x9cproximal endxe2x80x9d, as they relate to the devices and methods described herein, refer to the end of the device closer to or in the direction towards the practitioner who might be applying the device or method, rather than the subject.
Objects of the invention include providing and employing screw-based means for rotational advancement and anchoring of catheters, probes, occluders, stents, and dilators into genitourinary and gastrointestinal passageways such as the urethra, ureter, esophagus and fallopian tube, and for the emplacement of suprapubic catheters for draining genitourinary organs such as the bladder, whereby the subject device is applied through a natural body orifice or surgically created opening and is drawn through the passage by the longitudinal pull of a helix on the walls of the passage or organ as the device is rotated. This technology is a radical departure from the 4000 year old traditional xe2x80x9cpush to advancexe2x80x9d methodology previously discussed.
Indwelling and Intermittent Catheters
Flexible, thin wall indwelling and intermittent catheters and related devices and delivery stylets, made possible by this form of emplacement, are less traumatic and easier for the medical practitioner or patient to use. The catheter of the invention eliminates the problems of conventional devices by using helix or rotational technology that provides controlled insertion and flexibility to negotiate the urethra. The helix design accomplishes a pre-dilatation of the passageway at a steady rate that relaxes the sphincter and lessens or prevents spasm. Once placed, the device is anchored by the radial displacement and close pitch of the helix, preventing longitudinal migration due to body movement or fluid flow.
In another embodiment, the helix is located on the shaft under a Foley-type balloon and disappears when the balloon is inflated. The flexible reinforced shaft need be only about half the wall thickness of conventional Foley Catheters, which means a smaller OD catheter can be used. The helix advances the shaft and dilates the urethra as the catheter is inserted. Once the bladder is reached the balloon is inflated with sterile water, the helix is engulfed by the balloon. The process is then reversed to remove the catheter. This technology fosters reduced costs for patent care, improved clinical outcomes and enhanced patient quality of life.
Continence Catheter with Valve
The continence catheter of the invention, indicated for bladder outlet obstructions, is intended for BPH patients who are not able to, or choose not to undergo TURP. This embodiment of the invention allows the urethra in the area of the prostate to remain open. At the proximal (external end) of this catheter there may be a flow valve which can be depressed or otherwise opened to empty the bladder. The catheter may be produced as a sterile, single-use, disposable item that can be used once and replaced as needed.
The same embodiment of the catheter of the invention provides a female Stress UI sufferer with lifestyle benefits that greatly outperform absorbent products intended to manage this condition.
The patient simply inserts the catheter into the urethral opening and rotates the shaft to advance the catheter into the bladder. This can be done in the morning in the convenience of home. When the user needs to urinate, the valve end of the flexible shaft may be exposed through the clothing and the valve opened to empty the bladder. Since the device is not removed and reinserted after each voiding the risk of infection is reduced. At the end of the day the catheter is easily removed and disposed.
Intraurethral Valved Catheter
The male or female intraurethral valved catheter of the invention is indicated for bladder control. This embodiment of the invention allows the flow of urine to be controlled by a valve mechanism that is within the catheter. This valve may be actuated directly by insertion of a tool such as a stylet, or remotely by using a magnetic field device.
The intraurethral device reduces the potential for infection by eliminating the external tubing which can be an entry path for bacterial contamination. These catheters are typically 3.5 to 6.5 centimeters in length, depending on the anatomy, and have the helical element of the invention on the outer diameter of the body. The thread height of the helix may vary over it""s length, as an aid to the advancement and retention characteristics of the device. The sidewall of the catheter may be reinforced to resist collapsing due to contraction pressure. This catheter may be inserted in the urethra under fluoroscopy, using a detachable flexible stylet which keys into the proximal end of the catheter in a non-rotational fitment, and may be inserted in an outpatient procedure using topical anesthesia.
Stents
The stent of the invention, indicated for bladder outlet obstructions, keeps the urethra open in the area of the stricture. The stent body may be between 3.5 cm and 6.5 cm in length depending on the anatomy, and has a helical element on the outer diameter of the body to advance and retain the stent. The sidewall of the stent may have a reinforcement means to prevent collapsing due to prostate pressure. The stent can be inserted in the urethra under fluoroscopy, using a detachable flexible stylet which keys into the proximal end of the stent body, and may be inserted in an outpatient procedure using topical anesthesia.
The stents of the invention are not susceptible to being incorporated by the urethral mucosa in a manner preventing rotation, thereby permitting a lengthy period of emplacement and subsequent removal by the same rotational technique. The stent may also have a sufficiently large internal diameter, or lumen, to permit cystoscopies, thereby allowing examination of the bladder without removing the stent.
Dilators and Occluders
Helically-adapted dilators and occluders of the invention are likewise rotatingly advanced and retracted; the helical element performing a dilatory function to some degree. Dilators of respectively larger diameters may be used to achieve a gradually more pronounced effect The rotational advancement means may be combined with the push-to-advance methodology in any of these devices. In a dilator, for example, a helically equipped leader shaft extending distally of the bulbous portion of the device rotatingly advances the device up to the point that the helix passes out of the interior end of the passage, the remainder of the leader shaft then providing a guide wire that leads the bulb through the remainder of the passageway when the dilator is pushed from the proximal end.
Suprapubic Catheters
The adaptation of the invention to suprapubic catheters used in a classic transabdominal puncture for the drainage of the bladder or other genitourinary organs, permits the helix on the distal end of the catheter to be emplaced in the wall of the organ far enough so that the helical vane extends from both sides of the organ wall, so that the longitudinal sliding motion of the catheter into and out of the organ is inhibited by the helical vane. This reduces a source of irritation and associated complications at the organ wall entry point.
The helically-adapted suprapubic catheter may be placed in the organ using ultrasound or fluoroscopy to visualize placement, by rotatingly advancing the catheter over a guidewire leading to the organ; the guidewire having been installed through a tubular access created by using a cannula and trocar to reach the organ, the trocar and the cannula having been successively removed.
General Construction
Any embodiment of the invention may be radiopaque, or have radiopaque features, markers or other components, permitting the use of fluoroscopy to monitor emplacement or removal of the device, or even the rotational orientation and rotational movement.
The thread element may be solid, hollow, or fluid filled. It may taper in height at various locations to optimize advancement and anchoring. Embodiments or elements of the invention may be fabricated, molded, wound, extruded or otherwise constructed of non-toxic, non-corrosive materials or combinations of materials that are otherwise tolerant of bodily fluids and durable when implanted in vivo. Such materials may include but are not limited to polyurethane, medical grade stainless steel, silicone, bicarbon, polytetrafluoroethylene, tantalum, titanium, or nickel-titanium alloy. Conversely, materials may be specifically chosen to be bioabsorable so as to obviate the need for removal.
The devices of the invention may be enhanced with one or a combination of the following coatings: water based hydrophilic, antibacterial coatings such as nitrofurazone, bateriostatic coatings such as silver, or other mediations to further enhance their clinical performance.
Camera Introducer
The threaded camera introducer system, briefly stated, presents a novel means for the introduction of sensors and other implements into and through the fall length of the colon. The fundamental structure of the introducer, consistent with the rotate-to-advance structure and methodology of the invention, is a large, soft, flexible worm-like tubular device with a helix of soft, pliant threads which translate rotational force at the proximal end to a pulling action on the colon wall.
The hollow core or central lumen connects the distal and proximal ends of the tube. A camera head or other visual sensor can be introduced into the device and arranged to xe2x80x9cseexe2x80x9d forward from the center of the bulbous tip on the distal end. Light bundles or wires connected to the camera pass through the central lumen and out the proximal end of the device to an appropriate control and viewing apparatus.
The distal end of the device is gently urged into the rectum sufficiently far to engage the helix. The device is rotated from just outside the point of entry, to slowly advance into and through the entire length of the colon to the cecum. The helical threads pulling the device gently along the interior colon wall; the flexibility of the device allowing it to easily negotiate the major turns of the colon. The larger threads at the distal end provide the greatest grip or pull, the smaller threads closer to the proximal end contributing a lesser degree of grip or pull. The device is removed using the same method in reverse.
As illustrated in the figures, the light bundles or cables may be encased in a flexible torque tube or assembly which provides or contributes to the torsional strength necessary to rotatingly advance and withdrawn the device.
The interior wall of the main tubular device or introducer, may be configured to contain the torque tube or vertebra in a non-rotational manner, such that torque applied at any place on the exterior wall of the introducer is transmitted to the torque tube and hence over the full length of the device.
Various embodiments and enhancements are possible, all within the scope of the invention:
1. The helical thread or spiral extending the length of the device may be used for auxiliary purposes, including to:
a) Carry fluids into the colon/passage,
b) Provide vacuum to the passage way itself or vacuum within the device to facilitate the advancement of the camera or endoscope into the device,
c) Convey light bundles or electrical wires for specific purposes, and/or
d) Provide depth markers to assist the practitioner in determining the general position of the device within the body.
2. The spiral may also be inflated with a fluid during entry to obtain fall thread form and rotationally grip or fix the catheter to the camera element, and deflated to permit non-rotational removal by pulling the device through the colon.
3. The video screen or the image on the screen as seen through the rotating camera introducer as it advances, may be electronically processed to hold the image in a non-rotating, stationary manner for the benefit of the person administering the procedure.
4. The distal portion of the device may be relatively more flexible to enhance trackability along the path of the colon/passageway.
5. The device may have sufficient torque transmission capability from the proximal to the distal end so the distal portion of the device can be thus rotated at full length in the colon without interior support.
6. The distal tip or zone may have a sufficient thread height to grip the colon wall and provide the primary xe2x80x9cpulling powerxe2x80x9d to advance the device into the body and negotiate the turns, while the somewhat lower thread height along the balance of the device is adequate to support rotational advancement without drag and avoid bunching or gathering the colon wall.
7. There are at least three methods of containing and controlling this 160 cm long instrument to ensure it remains within the operating field:
a) A dispensing device as shown in FIG. 34,
b) A straight tubular component, or
c) Held by an assistant.
8. Material of construction:
a) The main body may be produced from polyvinylchloride plastic and may be reinforced with wire or fabric.
b) The helix may be made of PVC and may be reinforced with wire or otherwise.
c) A distal end window may be a flat, optically clear plastic lens made from PVC, polycarbonate, or acrylic plastic.
9. Alternative Uses:
a) Variations on the introducer device within the scope of the invention include full length tubes, or short sections analogous to urethral stents, being emplaced in the colon by the rotational structures and techniques of the invention for temporary purposes such as to aid in the repair of a damaged colon or a related abdominal injury or condition, by providing a supplemental lining and/or form to the colon or to a section of the colon.
10. Camera with torque control umbilicus:
a) The camera body which houses both the camera and the light sources may be made of stainless steel or molded with a dimensionally stable plastic such as polycarbonate.
b) The vertebrae which makes up the torque control umbilicus may be made of a high strength thermoplastic or a metal such as stainless steel or beryllium copper.
By means of the invention, the entire colon can be examined without the need for a conventional colonoscope or endoscope, and without the attendant expertise, pain, medication, post procedure recovery time, and cost. The means and method of the invention require less training and have far greater likelihood of reaching the cecum, (far end of the colon), than conventional tools and procedures. Other body cavities and passageways may be similarly examined.
The camera introducer catheter can be used in four different modes:
1. As an INTRODUCER, it includes the following characteristics and benefits:
a) Conveys a camera assembly along the entire colon to screen patients for polyps, lesions, cancer sights and other maladies.
b) The entire colon can be examined without the need for a conventional colonoscope/endoscope.
c) A total examination of the colon can be successfully performed with significantly less manipulation technique, pain, medication and post procedure recovery time.
d) Requires less training and has greater success in reaching the cecum.
e) As a single-use disposable device, allowing the expensive camera with its torque controlled umbilicus to be used repeatedly without danger of sequential infections.
f) Procedure is less expensive when compared to the cost of cleaning and repairing the conventional endoscopes and amortizing the cost of today""s costly video processing unit.
g) The procedure can be successfully performed by less specialized, less expensive individuals.
h) The INTRODUCER is supplied sterilized and ready for use.
2. As a more CONVENTIONAL STYLE ENDOSCOPE:
By adapting a conventional endoscope to the structure and method of the invention, the benefits of the invention are coupled with the following conventional functions:
a) Tip articulation.
b) Air and water delivery.
c) Suction of fluids.
d) Illumination of passages.
e) Imaging capability.
f) Drug delivery.
g) Accessories.
3. As a HYBRID CATHETER having some of the functions and features of the more CONVENTIONAL ENDOSCOPE and/or the INTRODUCER style built into the device for procedure-specific applications. Also, it could be used in conjunction with or independent of conventional endoscopic devices and accessories.
4. As a TRANSPORTER or introducer to deliver a conventional endoscope to any location of the colon or other passageway. This may occur by:
a) Providing a fluid tight envelope for the endoscope.
b) Providing a means for the endoscope to exit the distal end of the INTRODUCER to perform diagnostic/therapeutic procedures normally done with the endoscope.
Still other objects and advantages of the present invention will become readily apparent to those skilled in this art from the following detailed description, wherein I have shown and described preferred and other embodiments of the invention, simply by way of illustration of the best mode contemplated by me on carrying out my invention. As will be realized, the invention is capable of other and different embodiments, and its several details are capable of modifications in various obvious respects, all without departing from the invention.